Watlow LogicPro - Manual (Page 144)

Chapter 10: Function Blocks LogicPro User’s Guide
128 Watlow Anafaze Doc.# 28002-00 Rev 3.00
Figure 10.12 Less Than Function Block
Inputs
EN is the Less Than (LT) enable bit. A True condition of this
bit causes the comparison between A and B to occur. In a
program using Ladder logic, the value of EN is determined by
the Boolean evaluation of elements placed between the left
power rail and EN in the function block. In FBD programs, the
value of EN is determined by the Variable connected to EN. If
no contacts are placed on the rung before EN, the value of EN
is always True.
A is one comparison value. In Ladder logic, assign this input a
symbolic name or constant value in the
Assign Function
Block Symbolic Input/Output dialog box. In FBD, assign
a variable to this input in the Variable Assignment dialog
box. The range of values this Variable can assume is from -
32,768 to 32,767, including 0 for INT type Variables and -
2,147,483,648 to 2,147,483,647, including 0 for LONG type
Variables. If this Variable is assigned a value out of these
ranges, unpredictable results will occur.
B is another comparison value. In Ladder logic, assign this
input a symbolic name or constant value in the
Assign
Function Block Symbolic Input/Output dialog box. In
FBD, assign a variable to this input in the Variable
Assignment dialog box. The range of values this Variable
can assume is from -32,768 to 32,767, including 0 for INT type
Variables and -2,147,483,648 to 2,147,483,647, including 0
for LONG type Variables. If this Variable is assigned a value
out of these ranges, unpredictable results will occur.
Output
Q is the Less Than output bit. This bit is enabled and passes
power when the enable bit is True and the value of A is less
than the value of B.
Equal To (EQ)
The Equal To (EQ) function block, shown in Figure 10.13 on
page 129, tests if a value is equal to a reference value.